Federation on DB2 with Oracle

Hi Folks,

I have a Db2 environment Federated with Oracle, we face more of issues where the connections come in from application and it becomes stale connections .It grows and grows till we bounce the database.

Db2 : V9.7 FP7
Oracle: 11g release 2
OS: Aix 6.1

If you can help me to find the best practices for troubleshooting or tuning this.
Thanks